Six subjects will be started on treatment with dose level 1. After the sixth subject completes 84 days of treatment, if no dose-limiting toxicity occurs, then the next group of 6 subjects will be treated at the next higher dose regimen. If 1 of the 6 initial subjects experiences a DLT, the cohort of subjects will be expanded to 8 subjects. If fewer than two DLTs occur in 8 subjects, then the next higher dose group will be initiated. If 2 of the 6 initial subjects or 3 or more (of a cohort of up to 8) subjects experience DLTs, no further dose escalations will occur; the study will be discontinued and the MTD will have been exceeded.